I plan to study the production and regulation of placentally produced eicosanoids (prostacyclin, thromboxane, hydroxyeicosatetraenoic acids (HETEs) and leukotrienes) in both normal pregnancies and pregnancies complicated by hypertension (preecalmpsia). Preeclampsia is one of the leading causes of fetal growth retardation, premature delivery and maternal death. Human placental tissues will be incubated in vitro to study production rates and regulatory factors. Eicosanoids will be measured by radioimmunoassay. Specifically, I will study: 1) the regulation of placental prostacyclin and thromboxane production, and the etiology of their imbalance of increased thromboxane/decreased prostacyclin in preeclampsia; 2) the regulation of placental HETEs and leukotrienes and the etiology of the 5- and 12-lipoxygenase deficiencies in preeclampsia; 3) the regulatory interactions that exist between the cyclooxygenase (prostaglandins and thromboxane) and lipoxygenase (HETEs and leukotrienes products of arachidonic acid metabolism; 4) the production rates of leukotrienes in normal and preeclamptic placentas.